Since a large part of what he did was checking empirically, I don’t think your opinion is justified. Really, the most likely explanation is that he checked empirically—the same way he observed that the kidneys filter urine, that some sharks give birth to live young, and numerous other biological discoveries that were obtained in part through first-hand vivisection.
I don’t think that Aristotle did check empirically, though.
Since a large part of what he did was checking empirically, I don’t think your opinion is justified. Really, the most likely explanation is that he checked empirically—the same way he observed that the kidneys filter urine, that some sharks give birth to live young, and numerous other biological discoveries that were obtained in part through first-hand vivisection.